Self-locking tray



United States Patent 3,412,921 SELF-LOCKING TRAY Vernon C. Rekow, St.Paul, Minn., assignor to Hoerner- Waldorf Corporation, St. Paul, Minn.,a corporation of Delaware Filed Oct. 26, 1967, Ser. No. 678,388 2Claims. (Cl. 229-31) ABSTRACT OF THE DISCLOSURE This invention relatesto a tray which may be locked in set up form without the use of staples,adhesives or other such means. The tray includes a rectangular bottompanel having side walls hinged to two opposed parallel edges and endwalls hinged to the remaining opposed parallel edges. Triangular gussetflaps are hinged to the sides of the end walls and to the ends of theside walls, the gusset flaps at each corner being connected along foldlines which extend diagonally outwardly from the corners of the bottompanel. The gusset flaps hinged to the side walls include a flap hingedto the upper edge and folded between the end wall gusset flaps and theend wall panels. Liner flanges are hinged to the upper edges of the sidewalls and are folded between the parallel gusset flap structures to holdthe tray from unfolding.

This invention relates to an improvement in self-locking trays and dealsparticularly with a tray of paperboard which may be erected into trayformation without the use of staples, adhesives or other means forsecuring the corners of the tray connected.

Various types of trays have been produced which may be erected from aflat blank and locked in erected form. This is most commonly done byproviding corner flaps on the ends of two opposed walls designed to foldinto face contact with the inner surfaces of the other opposed walls,and folding a lining panel hinged to the upper edges of the otheropposed walls inwardly of the corner flanges and locking the liningpanels in this position. The trays thus formed cannot be liquid tightdue to the slots separating the corner flaps from the other opposedwalls. Furthermore, it is usually necessary to have the lining panels tofull height of the walls to which they are hinged in order to lock inplace.

An object of the present invention resides in the provision of a traywhich can be water-proof if it is so desired, and which is held erect bylining panels or flanges which extend only a portion of the height ofthe walls to which they are hinged. This arrangement results in a savingof paperboard, and a consequent saving in cost.

A feature of the present invention resides in the provision of a trayhaving a pair of triangular gusset flaps connected together along adiagonal fold line forming the corners of the tray. A flap is hinged tothe upper edge of the gusset flap which will be innermost and isdesigned to fold over the upper edge of the adjoining gusset flap tohold the gusset flaps in face contact. The flap is folded between thetwo gusset flaps and two opposed walls of the tray. Liner flanges areprovided hinged to the upper edges of the remaining two opposed trayside walls and the liner flanges are designed to fold between the gussetflaps at opposite ends of the tray to hold the tray erect.

These and other objects and novel features of the present invention willbe more clearly and fully set forth in the following specification andclaims.

In the drawings forming a part of the specification,

FIGURE 1 is a perspective view of the tray in erected position,

ice

FIGURE 2 is a perspective view of the tray in partially folded position.

FIGURE 3 is a diagrammatic view of the blank from which the tray isformed.

The tray which is indicated in general by the letter A is formed of theblank illustrated in FIGURE 3. As shown, the blank includes a bottompanel 10 of rectangular form connected along parallel fold lines 11 toend walls 12. The bottom panel 10 is foldably connected to side wallpanels 14 along parallel fold lines 13 which are in right angularrelation to the fold lines 11. The side walls 14 are connected alongdouble lines of fold 15 to liner flanges 16.

Triangular gusset flaps 17 are foldably connected to the sides of theend walls 12 along fold lines 19 which are substantially extensions ofthe fold lines 13. Similar triangular gusset flaps 20 are foldablyconnected to the ends of the side walls 14 along fold lines 21 which aresubstantially extensions of the fold lines 11. The gusset flaps 17 and20 at each corner of the blank are foldably connected along fold lines22 which extend diagonally outwardly from the four corners of the bottompanel 10. Locking flaps 23 are hingedly connected to the gusset flaps 20along double fold lines 24 which are substantially aligned with thedouble fold lines 15.

In erecting the tray, the gusset flaps 17 and 20 are folded along thediagonal fold lines 22, the side walls 14 and end walls 12 beingsimultaneously folded upwardly along the fold lines 13 and 11. When thegusset flaps 17 and 20 are in face contact, they are first foldedagainst the side walls 14, the gusset flaps 20 which are hinged to theside walls being folded substantially into face contact with the sidewalls 14. When in this position, the locking flaps 23 are folded overthe upper edges of the gusset flaps 17 and folded downwardly of thegusset flaps 17. Each gusset flap structure is then folded through anangle of so that the gusset flaps 17 are in parallel relation with theend wall panels 12 to which they are hinged. This action causes thelocking flaps 23 to be sandwiched between the gusset flaps 17 and theend walls 12. The linear flanges 16 are then folded inwardly anddownwardly between the gusset flap structures at opposite ends of thetray, holding the gusset flap structures against the end walls andthereby preventing the tray from unfolding. In other words, instead offolding the liner flanges over the gusset flap structures to. enclosethem, the ends of the liner flanges engage between the gusset flapstructures to hold them against the end walls 12. In this way the linerflanges need not extend the full height of the side walls to which theyare hinged. The terms side wall panels and end wall panels are merelyfor reference and not to indicate the relative length of these panels.

I claim:

1. A tray including:

a rectangular bottom panel,

end walls hinged to opposite parallel edges of said bottom panel,

side walls hinged to opposite sides of said bottom panel,

said side and end walls extending upwardly from said bottom panel,

triangular gusset flaps hinged to the end edges of said side walls,

triangular gusset flaps hinged to the side edges of said end walls,

said triangular gusset flaps of said side walls being connected to thegusset flaps of said end walls along diagonal fold lines and folded inface contact,

locking flaps hinged to the upper edges of the gusset flaps hinged tosaid side walls and folded over the upper edges of the adjoining endwall panel gusset 3 4 flaps and between the end wall panel gusset flapsand References Cited the end walls, and liner flanges hinged to theupper edges of said side wall UNITED STATES PATENTS panels and foldedbetween the gusset flaps folded 2,629,535 2/1953 Ullrich 229-34 parallelto the end walls to hold the tray assemb ed- 5 3,963,210 12/1960Gillmore 229-3l 2. The structure of claim 1 and in which the lockingflaps and liner flanges are of equal length. DAVID M. BOCKENEK, PrimaryExaminer.

